| 英文摘要 |
Agitation rate is a critical parameter influencing microbial physiology, metabolite synthesis, and overall fermentation efficiency. This study investigated the effect of agitation rate on biomass growth, lactic acid production, and short-chain fatty acid (SCFAs) synthesis by Bifidobacterium bifidum TISTR 2129 in a stirred-tank bioreactor. Batch fermentations were conducted at agitation rates of 100, 300, and 500 rpm over 168 h using MRS broth under controlled microaerophilic conditions. The findings indicated that increased agitation significantly enhanced cell growth and lactic acid production. The maximum biomass concentration (5.8 g/L) and lactic acid yield (9.0 g/L) were achieved at 500 rpm, indicating enhanced substrate accessibility and activity by bacteria. SCFAs analysis indicated that the most varied and abundant metabolite profile was observed at 300 rpm, with lactic acid (2711.73 mg/L), acetic acid (618.77 mg/L), propionic acid (141.70 mg/L), and butyric acid (710.16 mg/L) identified. High agitation promoted fast biomass production, whereas moderate agitation (300 rpm) optimized lactic acid by ~52-fold compared to 100 rpm and by > 300-fold compared to 500 rpm. Based on the kinetic parameters presented for B. bifidum at different agitation rates (100, 300, and 500 rpm), the results of the fitted models (Monod, Logistic, and Gompertz) reveal several important insights into the microbial growth behaviour under varying oxygen transfer conditions. This study offers valuable information for the development of probiotic fermentation processes and facilitates the advancement of functional foods and pharmaceutical goods abundant in bioactive components. |
本站僅提供期刊文獻檢索。
